All NULL values are ignored in the total count.
9> CREATE TABLE sales(
10> stor_id char(4) NOT NULL,
11> ord_num varchar(20) NOT NULL,
12> ord_date datetime NOT NULL,
13> qty smallint NOT NULL,
14> payterms varchar(12) NOT NULL,
15> title_id varchar(80)
16> )
17> GO
1> insert sales values('1', 'QA7442.3', '09/13/94', 75, 'ON Billing','1')
2> insert sales values('2', 'D4482', '09/14/94', 10, 'Net 60', '1')
3> insert sales values('3', 'N914008', '09/14/94', 20, 'Net 30', '2')
4> insert sales values('4', 'N914014', '09/14/94', 25, 'Net 30', '3')
5> insert sales values('5', '423LL922', '09/14/94', 15, 'ON Billing','3')
6> insert sales values('6', '423LL930', '09/14/94', 10, 'ON Billing','2')
7> GO
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
1>
2>
3> select COUNT(qty) from sales;
4> GO
-----------
6
(1 rows affected)
1>
2> drop table sales;
3>
4> GO
1>